Peppermint and Ubuntu are the same its mean that peppermint is based on ubuntu.
Here i post few tricks from various sites to improve and fix ubuntu or peppermint.
https://ubuntu.com/download/alternative-downloads
https://peppermintos.com/
Trick number 1 update repositories we write in terminal :
And write our password
sudo gedit /etc/apt/sources.list and sources.list.save
then copy text from here and save :
https://gist.github.com/plonknimbuzz...e-sources-list
Later write : sudo apt update
By editing sources.list at the end of document we can add own software
Simple info about system is writting command :neofetch